#### Answer

Fail to reject Null Hypothesis. Hence there is no sufficient evidence that $µ_{1} - µ_{2} \ne 5$

#### Work Step by Step

$z = \frac{70-50-5}{\sqrt {100/100 + 64/100}}$
$= \frac{15}{1.64} = 9.146$
Since 9.146 > 1.96, we fail to reject Null Hypothesis